1. Field of the Invention
This invention relates to a circuit breaker having a faster acting trip unit and, more particularly, it pertains to a magnetic trip unit in which magnetic flux lines are concentrated between a core and armature.
2. Description of the Prior Art
The circuit-interrupting art is everchanging and compact circuit breakers have evolved that comprise overcurrent protective devices, or trip units, that function in response to such abnormal currents as overcurrents, ground fault currents, and short circuits that occur in an electrical distribution system. Such trip units are disclosed in U. S. Pat. Nos. 3,530,414; 3,797,007; 3,808,847; 3,815,064; 3,950,716; 3,950,717; 4,074,218; and 4,313,098. Although these circuit breakers have a greater range for adjusting for specific trip currents between maximum and minimum air gaps between the magnet and the armature of the trip units, there is a need for a device that provides for faster tripping action at a predetermined overcurrent condition. This is especially true for fast acting current limiting circuit breakers.